JPWO2017069195A1 - Colored adhesive tape and colored adhesive tape for fixing portable electronic device parts - Google Patents

Abstract

The present invention provides a colored pressure-sensitive adhesive tape in which a support layer and a colored shielding layer are peeled off even during rework and the like, and ink peeling does not occur, and a colored pressure-sensitive adhesive tape for fixing a portable electronic device component With the goal. The present invention is a substrate having a colored shielding layer on at least one surface of a support layer made of polyethylene terephthalate, and a colored adhesive tape having an adhesive layer on the surface of at least the colored shielding layer side of the substrate, The colored shielding layer is a colored adhesive tape having a Young's modulus at 23 ° C. of 6.0 GPa or less as measured by a nanoindentation method.

Description

The present invention relates to a colored adhesive tape in which a support layer and a colored shielding layer are not peeled off even during rework or the like, and ink peeling does not occur, and a colored adhesive tape for fixing portable electronic device parts.

In a portable electronic device (for example, a mobile phone, a portable information terminal, etc.) equipped with an image display device or an input device, an adhesive tape is used for assembly. Specifically, a window frame-shaped double-sided adhesive tape is used to bond a backlight unit (BLU) and a liquid crystal display (LCD), a magnetic sheet having magnetic permeability such as a ferrite sheet, and a portable information terminal. Double-sided or single-sided adhesive tape is used to bond a heat-dissipating sheet such as a graphite sheet for suppressing heat generation inside the portable information terminal.
Adhesive tapes used in portable electronic devices are required to have various performances including high adhesive strength. For example, in order to improve the visibility of a liquid crystal display, LED light, which is a light source of BLU, is formed into a window frame shape. For the purpose of completely shielding with this tape or concealing the surface of the adherend, an adhesive tape having high shielding properties is required.

As an adhesive tape having excellent shielding properties, for example, Patent Document 1 discloses a colored adhesive in which an adhesive layer is provided on at least one surface of a colored substrate having a resin film layer (support layer) and a colored layer (colored shielding layer). A colored pressure-sensitive adhesive tape is described in which the thickness of the resin film layer is 2 to 5 μm, the dynamic friction coefficient is 0.1 to 0.4, and the total thickness of the tape is 15 μm or less.

In recent years, there has been a demand for designs that make portable electronic devices thinner and lighter, and adhesive tapes have become even thinner, and extremely thin adhesive tapes having a total thickness of several μm to several tens of μm have been required. However, when trying to reduce the total thickness of the colored adhesive tape described in Patent Document 1, for example, when peeling the colored adhesive tape once pasted such as rework, the support layer and the colored shielding layer are peeled off, There has been a problem that ink peeling may occur.

JP 2013-72074 A

In view of the above situation, the present invention provides a colored adhesive tape that does not cause peeling of the support layer and the colored shielding layer during rework and the like, and a colored adhesive for fixing portable electronic device parts. The purpose is to provide a tape.

The present invention is a substrate having a colored shielding layer on at least one surface of a support layer made of polyethylene terephthalate, and a colored adhesive tape having an adhesive layer on the surface of at least the colored shielding layer side of the substrate, The colored shielding layer is a colored adhesive tape having a Young's modulus at 23 ° C. of 6.0 GPa or less as measured by a nanoindentation method.
The present invention is described in detail below.

The present inventor has examined the cause of ink peeling due to peeling of the support layer and the colored shielding layer during rework or the like in the conventional colored adhesive tape. In the colored adhesive tape, the support layer is usually subjected to a surface treatment such as corona treatment for the purpose of improving the adhesion between the support layer and the colored shielding layer. However, in applications where an extremely thin adhesive tape is required, the thickness of the pressure-sensitive adhesive layer must be a certain level or more in order to ensure sufficient adhesiveness, and the thickness of the substrate must be as thin as possible. In such a thin base material, it cannot withstand corona treatment or the like, and tearing or the like occurs, so that the support layer cannot be subjected to surface treatment. Even if a colored shielding layer is laminated on such an untreated support layer, sufficient adhesion cannot be obtained, and the support layer and the colored shielding layer are peeled off during rework or the like, causing ink peeling. It was thought to have been lost.
On the other hand, as a result of intensive studies, the present inventor achieved sufficient adhesion even when laminated on a support layer not subjected to surface treatment by setting the Young's modulus of the colored shielding layer to a certain value or less. The present inventors have found that a colored pressure-sensitive adhesive tape can be obtained in which the support layer and the colored shielding layer are peeled off even during rework and the ink does not peel off.

The colored pressure-sensitive adhesive tape of the present invention has a base material and a pressure-sensitive adhesive layer formed on at least one surface of the base material. The colored adhesive tape of the present invention may be a single-sided adhesive tape having an adhesive layer only on one surface, or may be a double-sided adhesive tape having an adhesive layer on both sides.

The base material has a multilayer structure having a colored shielding layer on one surface of the support layer. By forming a colored shielding layer on the support layer, high shielding properties can be imparted to the double-sided pressure-sensitive adhesive tape of the present invention.

The support layer is made of polyethylene terephthalate (PET). By using a support layer made of PET, a colored pressure-sensitive adhesive tape having sufficient strength and handleability can be obtained even if it is thin.
The thickness of the support layer is not particularly limited, but the present invention is particularly effective when the thickness is 9 μm or less. A support layer having a thickness of 9 μm or less cannot withstand corona treatment or the like and easily breaks, and it is difficult to perform surface treatment. The colored adhesive tape of the present invention has a thickness of 9 μm or less, and even when a support layer that cannot be subjected to surface treatment such as corona treatment is used, the support layer and the support layer are colored even during reworking or the like. The excellent effect that the ink is not peeled off due to peeling from the shielding layer can be exhibited.
The lower limit of the thickness of the support layer is not particularly limited, but substantially 1 μm is the lower limit.

The colored shielding layer has a Young's modulus at 23 ° C. of 6.0 GPa or less. By adjusting the Young's modulus of the colored shielding layer, sufficient adhesion is exhibited even to a support layer that has not been subjected to a surface treatment such as corona treatment, and the support layer and the colored shield are also used during rework. It is possible to exhibit an excellent effect that the layer does not peel off and ink peeling does not occur. This is because, by setting the Young's modulus of the colored shielding layer to 6.0 GPa or less, even if stress is applied to the support layer and the colored shielding layer during rework or the like, the stress is exerted by the extension of the flexible colored shielding layer. It is thought to ease. The Young's modulus of the colored shielding layer is preferably 5.8 GPa or less, and more preferably 5.5 GPa or less.
The lower limit of the Young's modulus of the colored shielding layer is not particularly limited, but is preferably 1 GPa or more from the viewpoint of the heat resistance of the colored adhesive tape.

In this specification, Young's modulus means the Young's modulus at 23 ° C. measured by the nanoindentation method. The nanoindentation method is a method of quantifying the hardness and elastic modulus of the outermost surface micro-part layer to be measured from the obtained load-displacement curve by pushing the indenter into the measurement object with a very small load. Specifically, for example, it is measured by the following method.
That is, a polyethylene terephthalate film (colored shielding film) laminated with a colored shielding layer is allowed to stand for 24 hours under conditions of 23 ° C. and 50% RH, and then cut into a size of 10 mm × 10 mm to prepare a sample for measurement. When the thickness of the support layer on which the colored shielding layer is laminated is 9 μm or less, a single-sided adhesive tape having a thickness of 55 μm (Sekisui Chemical Co., Ltd.) is applied to the non-measurement surface of the colored shielding film cut to a size of 10 mm × 10 mm. (Product # 550M5BS) may be pasted and used as a sample for measurement. A glass plate is fixed to a sample stage, an epoxy adhesive is applied on the glass plate, and the non-colored shielding layer side (non-measurement surface) of the colored shielding film is fixed on the glass plate. For example, Nano Indenter XP / DCM (manufactured by Keysight Technologies) or the like is used as a measuring device, and the Young's modulus of the shielding layer surface of the colored shielding film is measured. Here, XP can be used as an indenter head, and a Barcovic type made of diamond can be used as an indenter. The measurement conditions are CSM (continuous stiffness measurement) as the measurement mode, the excitation vibration frequency is 45 Hz, the excitation vibration amplitude is 2 nm, the strain rate is 0.05 s ⁻¹ , the indentation depth is 2000 nm, the number of measurement points N is 15, and the measurement points The interval can be 100 μm, the measurement temperature can be 23 ° C., and the standard sample can be fused silica. Also, Test Works 4 (manufactured by Keysight Technologies) as analysis software can be used. In this specification, the average value measured at 15 points is defined as the Young's modulus.

The colored shielding layer is not particularly limited, but since a colored shielding layer can be easily formed on the support layer by a printing method, a colored shielding layer using an ink composition containing a pigment or a dye and a binder resin is preferable. It is.

It does not specifically limit as said pigment or dye, A conventionally well-known pigment or dye can be used. When the pigment or dye is black, for example, carbon black or titanium black can be used. When the pigment or dye is white, for example, titanium oxide, calcium carbonate, barium sulfate or the like can be used. As other colors, yellow iron oxide (yellow), red bean (red), cyanine blue (blue) and the like can be used. Among these, carbon black is preferable because it can exhibit particularly high shielding properties.

It does not specifically limit as said binder resin, For example, binder resin, such as a polyester type, an acrylic type, a urethane type, can be used. Of these, polyurethane-based binder resins are preferred because of their excellent adhesiveness and easy printing.

The Young's modulus of the colored shielding layer can be adjusted by the glass transition temperature (Tg) of the binder resin and the blending amount of the pigment or dye.
That is, by selecting a binder resin having a low glass transition temperature (Tg), the Young's modulus of the colored shielding layer can be lowered. Specifically, for example, in a polyester-based, urethane-based, and acrylic-based binder resin, the binder resin is selected based on a glass transition temperature (Tg) of 45 ° C. or lower. Here, the glass transition temperature (Tg) means a value obtained by measuring only the colored shielding layer with a differential scanning calorimeter.
From the viewpoint of lowering the Young's modulus, the glass transition temperature (Tg) of the binder resin is more preferably 0 ° C. or lower. In addition, since the tolerance with respect to a solvent may become weak when a glass transition temperature (Tg) is too low, -20 degreeC or more is preferable for the glass transition temperature (Tg) of binder resin.
Further, when the amount of the pigment or dye is increased, the Young's modulus of the colored shielding layer is increased, and when the amount of the pigment or dye is decreased, the Young's modulus of the colored shielding layer is decreased. In order to adjust the Young's modulus of the colored shielding layer while ensuring sufficient shielding properties, the preferred lower limit of the weight ratio of the binder resin to the pigment or dye (pigment or dye / binder resin) is 0.5, preferably The upper limit is 1.5. A more preferred lower limit of the weight ratio of the binder resin and the pigment or dye is 0.6, a more preferred upper limit is 1.2, a still more preferred lower limit is 0.8, and a still more preferred upper limit is 1.0.

Although the thickness of the said colored shielding layer is not specifically limited, A preferable minimum is 5 micrometers and a preferable upper limit is 8 micrometers. When the thickness of the colored shielding layer is within this range, sufficient shielding properties can be exhibited while suppressing the thickness of the colored adhesive tape. The minimum with more preferable thickness of the said colored shielding layer is 6 micrometers, and a more preferable upper limit is 7 micrometers.

The preferable lower limit of the thickness of the substrate (the total thickness of the support layer and the colored shielding layer) is 1 μm, and the preferable upper limit is 9 μm. When the thickness of the base material is within this range, the total thickness is sufficiently thin, and a colored adhesive tape having both high shielding properties and adhesiveness can be obtained. The minimum with more preferable thickness of the said base material is 2 micrometers, and a more preferable upper limit is 6 micrometers.

The method for forming a colored shielding layer on one surface of the support layer is not particularly limited, and an ink composition containing the pigment or dye and a binder resin on the support layer, a gravure printing method, a flexographic printing method, Examples thereof include a method of printing by a printing method such as a screen printing method and an offset printing method, and a direct coating method of coating using a comma coater.

The colored pressure-sensitive adhesive tape of the present invention has a pressure-sensitive adhesive layer on at least the colored shielding layer side surface of the substrate.
In the colored pressure-sensitive adhesive tape of the present invention, the pressure-sensitive adhesive layer may be disposed directly on the colored shielding layer, and, for example, another colored layer or the like between the colored shielding layer and the pressure-sensitive adhesive layer. You may have a printing layer etc. Furthermore, when it has a colored shielding layer on both surfaces of the said base material, you may have an adhesive layer on the surface by the side of the colored shielding layer of either side.
When the colored pressure-sensitive adhesive tape of the present invention is a double-sided pressure-sensitive adhesive tape, the double-sided pressure-sensitive adhesive layers may have the same composition or different compositions.

The adhesive which comprises the said adhesive layer is not specifically limited, A conventionally well-known adhesive can be used. Especially, since it can exhibit high adhesive force even if it is thin, an acrylic adhesive is preferable, and an acrylic adhesive containing an acrylic copolymer having a structural unit derived from butyl acrylate and 2-ethylhexyl acrylate is more preferable.

The minimum with preferable content of the structural unit derived from the butyl acrylate in the said (meth) acrylic copolymer is 40 weight%, and a preferable upper limit is 80 weight%. When the content of the structural unit derived from the butyl acrylate is within this range, high cohesive force, adhesive force, and tack can be exhibited.
The minimum with preferable content of the structural unit derived from 2-ethylhexyl acrylate in the said (meth) acrylic copolymer is 10 weight%, and a preferable upper limit is 50 weight%. When the content of the structural unit derived from 2-ethylhexyl acrylate is within this range, high cohesive force, excellent adhesive force, and tack can be exhibited.

The (meth) acrylic copolymer may contain a structural unit derived from another copolymerizable monomer other than butyl acrylate and 2-ethylhexyl acrylate, if necessary.
Examples of other polymerizable monomers that can be copolymerized include, for example, carbon number of alkyl groups such as methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and isopropyl (meth) acrylate. 1 to 3 (meth) acrylic acid alkyl ester, tridecyl methacrylate, and (meth) acrylic acid alkyl ester having 13 to 18 carbon atoms such as stearyl (meth) acrylate, hydroxyalkyl (meth) acrylate , Glyceryl dimethacrylate, glycidyl (meth) acrylate, 2-methacryloyloxyethyl isocyanate, (meth) acrylic acid, itaconic acid, maleic anhydride, crotonic acid, maleic acid, fumaric acid, and the like.

The (meth) acrylic copolymer can be prepared by copolymerizing a monomer mixture containing the monomer. Specifically, the monomer mixture may be radically reacted in the presence of a polymerization initiator. As a method of radical reaction of the monomer mixture, that is, a polymerization method, a conventionally known method is used, and examples thereof include solution polymerization (boiling point polymerization or constant temperature polymerization), emulsion polymerization, suspension polymerization, bulk polymerization and the like.

The said polymerization initiator is not specifically limited, For example, an organic peroxide, an azo compound, etc. are mentioned. Examples of the organic peroxide include 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, t-hexylperoxypivalate, t-butylperoxypivalate, 2,5 -Dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxy Examples include isobutyrate, t-butylperoxy-3,5,5-trimethylhexanoate, and t-butylperoxylaurate. Examples of the azo compound include azobisisobutyronitrile and azobiscyclohexanecarbonitrile. These polymerization initiators may be used alone or in combination of two or more.

As for the weight average molecular weight (Mw) of the said (meth) acryl copolymer, a preferable minimum is 400,000 and a preferable upper limit is 2 million. When the weight average molecular weight of the (meth) acrylic copolymer is within this range, high cohesive force, excellent adhesive force, and tack can be exhibited. The minimum with a more preferable weight average molecular weight of the said (meth) acryl copolymer is 500,000, and a more preferable upper limit is 1,500,000.
In order to adjust the weight average molecular weight within the above range, polymerization conditions such as a polymerization initiator and a polymerization temperature may be adjusted.
In addition, a weight average molecular weight (Mw) is a weight average molecular weight of standard polystyrene conversion by GPC (Gel Permeation Chromatography: gel permeation chromatography).

The acrylic pressure-sensitive adhesive may contain a tackifier resin.
Examples of the tackifier resins include rosin ester resins, hydrogenated rosin resins, terpene resins, terpene phenol resins, coumarone indene resins, alicyclic saturated hydrocarbon resins, C5 petroleum resins, and C9 resins. Examples thereof include petroleum resins and C5-C9 copolymer petroleum resins. These tackifying resins may be used alone or in combination of two or more.

Although content of the said tackifying resin is not specifically limited, The preferable minimum with respect to 100 weight part of said (meth) acryl copolymers is 10 weight part, and a preferable upper limit is 60 weight part. When the content of the tackifying resin is within this range, the (meth) acrylic copolymer can be provided with excellent tack and tack.

In the acrylic pressure-sensitive adhesive, a cross-linking structure is formed between the main chains of the resin (the acrylic copolymer and / or the tackifying resin) constituting the pressure-sensitive adhesive layer by adding a cross-linking agent. Is preferred.
The said crosslinking agent is not specifically limited, For example, an isocyanate type crosslinking agent, an aziridine type crosslinking agent, an epoxy-type crosslinking agent, a metal chelate type crosslinking agent etc. are mentioned. Of these, isocyanate-based crosslinking agents are preferred.
The addition amount of the crosslinking agent is preferably 0.01 to 10 parts by weight and more preferably 0.1 to 3 parts by weight with respect to 100 parts by weight of the acrylic copolymer.

The preferred lower limit of the gel fraction of the pressure-sensitive adhesive layer is 5% by weight, the preferred upper limit is 60% by weight, the more preferred lower limit is 10% by weight, the more preferred upper limit is 50% by weight, and the still more preferred lower limit is 15% by weight. A more preferred upper limit is 40% by weight.
The gel fraction of the pressure-sensitive adhesive layer was determined by collecting W1 (g) of the pressure-sensitive adhesive layer, and immersing this pressure-sensitive adhesive layer in ethyl acetate at 23 ° C. for 24 hours, and removing the insoluble content with a 200-mesh wire mesh. The residue on the wire mesh is vacuum-dried, and the weight W2 (g) of the dry residue is measured, and calculated by the following formula (1).
Gel fraction (% by weight) = 100 × W2 / W1 (1)

Although the thickness of the said adhesive is not specifically limited, A preferable minimum is 1 micrometer and a preferable upper limit is 35 micrometers. When the thickness of the pressure-sensitive adhesive is within this range, a colored pressure-sensitive adhesive tape having a sufficiently thin total thickness and high adhesiveness can be obtained. The minimum with more preferable thickness of the said adhesive layer is 2 micrometers, and a more preferable upper limit is 20 micrometers.

The colored adhesive tape of the present invention preferably has a total light transmittance of 3% or less as measured by a method according to JIS K 7361. Since the total light transmittance is 3% or less, the colored pressure-sensitive adhesive tape of the present invention is thin and excellent in shielding properties suitable for use in bonding and fixing components constituting recent portable electronic devices to the device main body. It becomes. When the total light transmittance exceeds 3%, for example, when the ferrite sheet is used for bonding and fixing to a device body, the base of the ferrite sheet may not be sufficiently concealed. A more preferable upper limit of the total light transmittance is 2.5%, and a further preferable upper limit is 2%.
The total light transmittance can be measured using a haze meter (for example, Haze Meter NDH4000 manufactured by Nippon Denshoku Industries Co., Ltd.) at 23 ° C. and a humidity of 50%.

As a manufacturing method of the colored adhesive tape of this invention, the following methods are mentioned, for example.
First, an acrylic copolymer, a tackifier resin, and if necessary, a solvent is added to a crosslinking agent or the like to prepare a solution of the adhesive A, and the adhesive A solution is applied to the surface of the substrate. The solvent in the solution is completely removed by drying to form the acrylic pressure-sensitive adhesive layer A. Next, a release film is overlaid on the formed acrylic pressure-sensitive adhesive layer A so that the release treatment surface faces the acrylic pressure-sensitive adhesive layer A. By pressing the laminate with a rubber roller or the like, a single-sided pressure-sensitive adhesive tape having an acrylic pressure-sensitive adhesive layer on one side of the substrate and the surface of the acrylic pressure-sensitive adhesive layer covered with a release film can be obtained.
When the colored pressure-sensitive adhesive tape of the present invention is a double-sided pressure-sensitive adhesive tape, a release film different from the release film is prepared, and a solution of the adhesive B is applied to the release-treated surface of the release film. The laminated film in which the acrylic pressure-sensitive adhesive layer B is formed on the surface of the release film is prepared by applying and completely removing the solvent in the solution by drying. The obtained laminated film is superposed on the back surface of the base material on which the acrylic pressure-sensitive adhesive layer A is formed, with the acrylic pressure-sensitive adhesive layer B facing the back surface of the base material to produce a laminate. Then, by pressing the laminate with a rubber roller or the like, a double-sided pressure-sensitive adhesive tape having an acrylic pressure-sensitive adhesive layer on both surfaces of the base material and having the surface of the acrylic pressure-sensitive adhesive layer covered with a release film can be obtained. it can.

In addition, two sets of laminated films are produced in the same manner, and a laminated body is produced by superposing these laminated films on both sides of the base material with the acrylic adhesive layer of the laminated film facing the base material. Then, by pressing this laminate with a rubber roller or the like, a double-sided pressure-sensitive adhesive tape having an acrylic pressure-sensitive adhesive layer on both surfaces of the base material and the surface of the acrylic pressure-sensitive adhesive layer covered with a release film can be obtained. Good.

The use of the colored pressure-sensitive adhesive tape of the present invention is not particularly limited, but the use of bonding and fixing components constituting the portable electronic device to the device main body is preferable. Specifically, the adhesive unit for the backlight unit (BLU) and the liquid crystal display (LCD), a magnetic sheet having a magnetic permeability such as a ferrite sheet, and a heat radiating sheet such as a graphite sheet for suppressing heat generation of the portable information terminal. The colored pressure-sensitive adhesive tape of the present invention can be used for adhesively fixing inside a portable information terminal.
A colored adhesive tape for fixing a portable electronic device component comprising the colored adhesive tape of the present invention is also one aspect of the present invention.
The shape of the colored adhesive tape for fixing a portable electronic device component of the present invention is not particularly limited, and examples thereof include a rectangle, a frame shape, a circle, an ellipse, and a donut shape.

According to the present invention, there are provided a colored adhesive tape that does not cause peeling of the support layer and the colored shielding layer during rework and the like, and a colored adhesive tape for fixing portable electronic device parts. can do.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Example 1
(1) Preparation of substrate SKK1C Black-B manufactured by Dainichi Seika Kogyo Co., Ltd. (20.5 parts by weight of a polyester resin having a glass transition temperature (Tg) of −5.9 ° C. as a binder resin, and an average particle diameter of 340 nm as a pigment) In addition, 100 parts by weight of an ink mainly composed of 12.3 parts by weight of carbon black having a median particle size of 320 nm) 5 parts by weight of VM-AL L8 manufactured by Dainichi Seika Kogyo Co., Ltd. as a curing agent, and an organic solvent Lamic F NO. 20 parts by weight of two solvents were mixed to obtain an ink composition. In addition, the average particle diameter and median particle diameter of the pigment contained in SKK1C Black-B were measured using a laser diffraction / scattering particle size distribution measuring apparatus LA-950 manufactured by Horiba.
The ink composition was applied to one surface of a support layer made of a polyethylene terephthalate film having a thickness of 6 μm, dried by gravure printing, and then cured at 40 ° C. for 36 hours to form a colored shielding layer having a thickness of 5 μm.
About the obtained colored shielding layer, it was 1.49 GPa when the Young's modulus in 23 degreeC was measured by the nanoindentation method.

(2) Preparation of pressure-sensitive adhesive A reactor equipped with a thermometer, a stirrer, and a condenser tube was 70 parts by weight of butyl acrylate, 27 parts by weight of 2-ethylhexyl acrylate, 3 parts by weight of acrylic acid, and 0.1 parts by weight of 2-hydroxyethyl acrylate. Then, 80 parts by weight of ethyl acetate was added and purged with nitrogen, and then the reactor was heated to start refluxing. Subsequently, 0.1 part by weight of azobisisobutyronitrile was added as a polymerization initiator in the reactor. The mixture was refluxed at 70 ° C. for 5 hours to obtain an acrylic copolymer solution. When the weight average molecular weight of the obtained acrylic copolymer was measured by a GPC method using “2690 Separations Model” manufactured by Water as a column, it was 710,000.
10 parts by weight of rosin ester (Arakawa Chemical Industries, Pencel D135) and 10 parts by weight of terpenephenol (manufactured by Yasuhara Chemical Co., Ltd.) with respect to 100 parts by weight of the solid content of the acrylic copolymer contained in the obtained acrylic copolymer solution. YS Polystar T130), 125 parts by weight of ethyl acetate (Fuji Chemical Co., Ltd.) and 2 parts by weight of an isocyanate-based crosslinking agent (Nihon Polyurethane Co., Coronate L45) were added and stirred to obtain an acrylic adhesive. It was.

(3) Manufacture of colored adhesive tape A release film (PET38x1A3, manufactured by Nipper Co., Ltd.) having a thickness of 38 μm is prepared, and the final solid content is obtained by diluting the release film with the acrylic adhesive (ethyl acetate). 20%) was applied and dried at 100 ° C. for 3 minutes to form an acrylic pressure-sensitive adhesive layer having a thickness of 10 μm. This acrylic pressure-sensitive adhesive layer was bonded to the colored shielding layer surface of the substrate and cured at 40 ° C. for 48 hours to obtain a colored pressure-sensitive adhesive tape.

(Examples 2-11, Comparative Examples 1-4)
A colored adhesive tape was obtained in the same manner as in Example 1 except that the composition of the ink composition was as shown in Tables 1 and 2.

(Examples 12 and 13)
In the same manner as in Examples 1 and 11, a colored shielding layer having a thickness of 5 μm was formed on one surface of a support layer made of a polyethylene terephthalate film having a thickness of 6 μm.
5 parts by weight of a white ink (Dai-Nichi Seika Kogyo Co., Ltd., Lamic F 701 white) as a curing agent (Dai-Ni Seika Kogyo Co., Ltd., Lamic B Hardener) and an organic solvent, Lamic F NO. A white ink solution was prepared by mixing with 20 parts by weight of two solvents. The white ink solution was applied onto the colored shielding layer by a gravure printing method to form a white printing layer having a thickness of 7 μm.
A release film having a thickness of 38 μm (Nippa's PET38x1A3) was prepared, and the release agent surface of this release film was obtained in the same manner as in Example 1 (diluted with ethyl acetate, final solid content 20 %) And dried at 100 ° C. for 3 minutes to form an acrylic pressure-sensitive adhesive layer having a thickness of 10 μm. This acrylic pressure-sensitive adhesive layer was bonded to the surface of the white printed layer of the base material and cured at 40 ° C. for 48 hours to obtain a colored pressure-sensitive adhesive tape.

<Evaluation>
The following evaluation was performed about the colored adhesive tape obtained by the Example and the comparative example. The results are shown in Tables 1 and 2.

(1) Evaluation of reworkability (vs. polycarbonate plate)
The obtained colored adhesive tape was allowed to stand at 23 ° C. and 50% RH for 24 hours, and then cut into a size of 10 mm × 200 mm to prepare a measuring tape.
A measuring tape was affixed to a polycarbonate plate having a thickness of 50 mm × 125 mm × 2 mm, and was pressure-bonded at 300 mm / min · 1 reciprocation using a 2 kg rubber roller. Immediately after the pressure bonding, it was heated at 85 ° C. for 24 hours, and then cured at 23 ° C. and 50% RH for 3 hours.
Then, the 180 degree peeling test was implemented by the method according to JISZ0237: 2009 (peeling speed is 300 mm / min). The transition (ink peeling) of the colored material on the surface of the adherend after the peeling test was visually confirmed, and sensory evaluation of rework characteristics was performed according to the following criteria.
○: No transfer of colored substances was observed.
(Triangle | delta): The transfer of the colored material was confirmed slightly.
X: It was confirmed that the colored material was transferred to the entire surface.

(2) Evaluation of reworkability (vs. glass plate)
Evaluation was performed in the same manner as for the polycarbonate plate except that the adherend was changed to a glass plate of 50 mm × 125 mm × 2 mm thickness.

(3) Evaluation of solvent resistance The surface of the colored shielding layer was rubbed 3 times with a cotton swab sufficiently soaked in ethyl acetate to confirm whether the colored shielding layer was transferred to the cotton swab, and evaluated according to the following criteria.
○: No transfer of coloring matter was observed on the cotton swab.
(Triangle | delta): The transfer of the colored material was slightly confirmed on the cotton swab.
X: It was confirmed that the colored material was transferred to the entire surface.

According to the present invention, there are provided a colored adhesive tape that does not cause peeling of the support layer and the colored shielding layer during rework and the like, and a colored adhesive tape for fixing portable electronic device parts. can do.

Claims (3)

A base material having a colored shielding layer on at least one surface of a support layer made of polyethylene terephthalate, and a colored pressure-sensitive adhesive tape having an adhesive layer on at least the colored shielding layer side surface of the base material,
The colored pressure-sensitive adhesive layer, wherein the colored shielding layer has a Young's modulus at 23 ° C. of 6.0 GPa or less as measured by a nanoindentation method. The colored adhesive tape according to claim 1, wherein the support layer has a thickness of 9 μm or less. A colored pressure-sensitive adhesive tape for fixing portable electronic device parts, comprising the colored pressure-sensitive adhesive tape according to claim 1.